The Impossibility of Flying Heavy Aircraft Without Training

In article X07Mf.34630$Ug4.15600@dukeread12, Dan says...

Chuck, um, ask Moller how to get gummint grants to pursue your
research. You may be onto something.


He would be the guy to ask :-)

As for the aviator looping, spinning and rolling a cow must you bring
Zoom into this?

I didn't you did :-) But no matter, now that I've explained flight I'm off to
find out what happens if you put insulated windows in backwards. Do they then
let the heat in during the summer and the cold in during the winter? Send money
for that reasearch as well

Cheers

Chuck (Wax on, Wax off) S

Occom's Razor, Jose.

Yes, but Occam's razor needs to work with theories that explain the
facts. Fact is, the down on an airplane =is= laterally separated from
the up, and airplanes fly only when they move forward.

If Occam's razor were so simple, we wouldn't have million dollar grants.

Jose
--
Money: what you need when you run out of brains.
for Email, make the obvious change in the address.

On 25 Feb 2006 19:50:00 -0800, ChuckSlusarczyk
wrote:

I didn't you did :-) But no matter, now that I've explained flight I'm off to
find out what happens if you put insulated windows in backwards.

You do know about the newlyweds who didn't know the difference between
KY Jelly and window putty?

(Scroll down.)




















All their windows fell out.

Son

Worse, the plumbers union.


"Dan" wrote in message
news:1Z6Mf.34567$Ug4.25620@dukeread12...
| Jim Macklin wrote:
| Cup holders allowed drinking in flight and that in turn
| required "draining the pilot's sump" more often in
flight.
| This required relief tubes, but then women started
flying
| and that requires the potty. The potty requires
plumbing
| and that means plumbers. More money "down the drain"
[pun
| intended] and then the government started buying toilet
| seats and we all heard what THAT cost.
|
|
| Maybe we could try to build a jet engine that burned
paper
| trash instead of petroleum products. This could save a
lot
| of oil and several steps in the process of flight, they
| could just directly burn money.
|
|
|
| The oil companies will be knocking at your door soon
|
| Dan, U.S. Air Force, retired

Or KY and BenGay Ouch



"Don Tuite" wrote in
message ...
| On 25 Feb 2006 19:50:00 -0800, ChuckSlusarczyk
| wrote:
|
| I didn't you did :-) But no matter, now that I've
explained flight I'm off to
| find out what happens if you put insulated windows in
backwards.
|
| You do know about the newlyweds who didn't know the
difference between
| KY Jelly and window putty?
|
| (Scroll down.)
|
|
|
|
|
|
|
|
|
|
|
|
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|
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| All their windows fell out.
|
| Son

ChuckSlusarczyk wrote:
In article X07Mf.34630$Ug4.15600@dukeread12, Dan says...

Chuck, um, ask Moller how to get gummint grants to pursue your
research. You may be onto something.


He would be the guy to ask :-)

As for the aviator looping, spinning and rolling a cow must you bring
Zoom into this?

I didn't you did :-) But no matter, now that I've explained flight I'm off to
find out what happens if you put insulated windows in backwards. Do they then
let the heat in during the summer and the cold in during the winter? Send money
for that reasearch as well

Cheers

Chuck (Wax on, Wax off) S



If you put them in upside down with the outdoors look inverted?
Remember to tip your cow according to services rendered.

Dan, U.S. Air Force, retired

I'd like to take a moment and wander off into fantasy land here...
For what it's worth?

In respect to whatever bizarre principles are really at work holding
an airplane up in the sky, I think some of us only are only seeing
the "down" side.

I'd like, for a moment, to address the "up" side.

We can easily imagine a column of air that extends from the bottom
side of the wing - all the way to the ground.
Very Newtonian.

Sure, the high pressure under the wing PUSHES UP on the wing.

But at the same time the low pressure above the wing PULLS UP on it.

And I suspect that "pulling up" part is a little harder to visualize.
What, for instance, is it pulling AGAINST?

There doesn't seem to be anything solid up there to pull against.
Except a lot of empty sky?

Theory:
This is my over simplified "localized pressure field" theory.

In flight our wing is "compressing" the air under it (down), while
at the same time "stretching" the air above it (also down).
(Both are allowed by the compressibility of subsonic gassious fluids)
The combined reaction is, of course, Lift (UP).

These pressure fields, while strong near the wing are proportionally lower
as we get farther from the wing surface (unlike a simple spring network).

I think of it as the pressure field being spread out over a larger volumn,
rather than being dissipated in a smaller column.

This also might address the question of what happened to the "momentum"
imparted to the air that we might expect if we only consider the down
side. The two pressure fields pretty well cancel each other out after
the wing has passed by.

Stalls:
At some value of high alpha, the low pressure ABOVE the wing exceeds
the shear value (viscosity) of air, and the flow "tears" loose.

For fat airfoils this happens much further aft that for thin airfoils,
which tend to separate nearer the leading edge.


Psychic Hotline:
Why does the air flow start to rise BEFORE it meets the wing?

If we look at an idealized flow diagram in a text book, (which usually
implies that the air is moving and the wing is stationary!?) we notice
that there is a high pressure area right at the leading edge of the wing.
Think of it as impact pressure.

Combine this with the low pressure area above and high pressure below and
we can see why the air seems to start rising BEFORE it gets to the wing.

Scope:
Now, how far these forces extend above and below the wing depends on
several factors - weight, CL, velocity of the wing, etc.

In straight and level flight, the wing generates as much lift as the
aircraft weighs. (Lift = weight)

So?
Higher speed, lower CL - smaller pressure field disturbance?
Lower speed, higher CL - higher pressure field disturbance?
(PER unit volumn / time)
The net work is the same same though. Lift = Weight

Tip Vortices:
Wing tip vortices are a direct result of these two pressure areas.
The high pressure below and the low pressure above tend to pull the air
_around_ the wing tip, inducing the circulation for the vortex.

This also rolls back into the question of why the vortex is a lot stronger
at low speeds. There is simply a much higher pressure difference between
the top and bottom fields.

And explains why winglets can help to reduce the vortex size, and the
induced drag that comes along with them.

Ground Effect:
As we get down to within a wing span or so of the ground, and the higher
pressure on the bottom side actually does come into contact with the ground,
said high pressure area under the wing gets trapped and is noticibly stronger.

Anyone who has tried to plant a Taylorcraft a little too fast knows this
*problem* intimately!


Summation:
This is, obviously, NOT the final word in aerodynamic phenonomnon, and
I offer it only as a (hopefully) useful picture of the forces in play.

I've ignored a lot of other obvious stuff - like Drag (because it's such a -
DRAG!), circulation theory, etc.

Like I said, "for what it's worth".

Richard

Disclaimer: All puns are the sole responsibility of the author and do
not imply any such foolish thoughts on behalf of the management...

Bryan Martin wrote:
The low pressure above the wing never pulls up on the wing at all, it just
doesn't push down as hard as the high pressure below so the net force is up.
Suction is not the opposite of pressure, suction doesn't really exist at
all, it is merely a term used to describe a lower pressure.


I'm going to gently disagree, Bryan.

If the pressure above the wing is below ambient, it sucks...

Richard Lamb wrote:

Bryan Martin wrote:
The low pressure above the wing never pulls up on the wing at all, it
just doesn't push down as hard as the high pressure below so the net
force is up. Suction is not the opposite of pressure, suction doesn't
really exist at all, it is merely a term used to describe a lower
pressure.


I'm going to gently disagree, Bryan.

If the pressure above the wing is below ambient, it sucks...
If it looks like a potato, smells like a potato and taste like a potato it
probably isn't a Tomato!
;-)

On 2006-02-24, Greg Esres wrote:
There is a *net* downward momentum of air.

I have several aerodynamics books that say differently.

Otherwise there is no lift.

If there is a pressure difference between the top and bottom, you will
have lift. Your airfoil is blisssfully unaware of the air with which
it has no contact.

But air acts as a fluid. The airfoil certainly DOES have an effect on
air that it has no contact.
If you think there is no downward movement of air from an airfoil, stand
underneath a hovering helicopter some day. Or behind the propellor of a
plane - the prop is also an airfoil.

You might be able to get lift out of an airfoil in an enclosed tube with
no downward movement of the air, but that won't happen in the real
world.

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
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